Device for reducing the volume of bottle made of plastic material

ABSTRACT

The apparatus according to the invention comprises a housing or frame for receiving the bottle, an element for fixing the bottle, a heating element surrounding part of the bottle and compressing means for compacting the softened bottle, wherein the housing or frame is constructed to receive the bottle with its mouth part upwards, the heating element or the part of the heating element surrounding the bottle is at most 60 mm high, and is arranged around the neck part of the bottle in its starting position and the fixing element is a sealable plug in the compressing means, to be fitted into the mouth of the bottle and having an air channel, the cross section of which is preferably adjustable, preferably with flow control means. The flow control means may be a valve.

The invention relates to an apparatus for compacting empty plasticbottles, comprising a housing or frame, means for fixing the bottle,means for heating a part of the bottle and a press unit for compactingthe softened bottle.

It is known that beverages and other food products are filled more andmore often into plastic bottles for sale, and the manufacturers want toproduce rather one-way bottles than repurchasable ones. Thus, thesebottles get in large amounts to waste yards or into nature,contaminating thereby the environment or increasing to a great extentthe amount of waste.

A further problem is caused by the fact that the material of theplastics do not decompose, thus the damage caused by them islong-lasting.

In order to eliminate, at least partly, the above problem, a greatnumber of suggestions were made for the domestic annihilation orcompacting of such bottles.

The solution is not easy due to the fact that plastic bottles, opposedto metal containers or boxes, regain a significant part of their volumeafter stopping the compression. Thus, compacting can only be performedby using compacting and thermal effect simultaneously, wherein thethermal effect does not allow the bottles to increase their volume afterceasing the compression, as a consequence of their elasticity. If,namely, bottles are compressed in their melted state, they do not changetheir form after cooling down.

Known bottle compactors generally comprise a housing or frame receivingthe bottle, heating means and compressing means.

EP 0707932 discloses a bottle compactor containing a housing chamberdesigned to receive an empty bottle. The housing is provided with aresistor and a cursor, the end of which is formed like a fork engagingthe plastic bottle at its neck part. The cursor with the fork compressesthe heated and softened bottle from the upside down. The cursor can beoperated manually by means of a lever.

FR 2694722 describes a portable device, wherein the power for compactingthe bottle arranged in a housing having resistance heating is providedby a spring.

In the bottom of the apparatus described in FR 2668732, there is aseparate heating chamber wherein air is heated by resistance heating andthe heated air is pulsed by a fan into a volume containing the plasticbottle, which is compacted by a plate moved by motor driven spindles.

In all the above devices, the bottles are heated from below, and theyare usually compressed from above. As a result, the folded plasticlayers are irregular and, in this way, optimal compression can not beachieved.

In other devices, heating is provided along the whole length of thedevice and/or by means of a patron intruding into the bottle. Such anapparatus is described e.g. in FR 2692190. In this case, the abovementioned disadvantage, namely the irregular compacting is especiallyobvious and, in addition, the energy consumption increases significantlyas well.

In FR 2712230 the disclosed apparatus has a closed housing with acentral heater intruding into the bottle which is compressed both fromtop to bottom and from bottom to top. The disadvantage of this is theunnecessarily increased energy requirement of compression and, furtheron, it is complicated and expensive.

The object of the present invention is to provide a cheap and simpledevice for compacting empty plastic bottles to the maximum achievabledegree and with a regulated, optimum compression rate.

Accordingly, the apparatus according to the invention comprises ahousing or frame for receiving the bottle, an element for fixing thebottle, a heating element surrounding part of the bottle and compressingmeans for compacting the softened bottle, wherein the housing or frameis constructed to receive the bottle with its mouth part upwards, theheating element or the part of the heating element surrounding thebottle is at most 60 mm high, and is arranged around the neck part ofthe bottle in its starting position and the fixing element is a sealableplug in the compressing means, to be fitted into the mouth of the bottleand having an air channel, the cross section of which is preferablyadjustable, preferably with flow control means. The flow control meansmay be a valve.

The compression means and the fixing element for the bottle is a lid orthe like moving on vertical guide bars and compressing the bottletowards the base of the housing, by its weight. The lid can also belifted and lowered by a spindle driven by an electric motor or by springmeans.

Preferably, the diameter of least one section of the plug is adjustable,being an elastic rubber or plastic sleeve and allowing the sealedclosing of the mouth of the plastic bottle.

In a preferred embodiment, the height of the heating element does notexceed 60 mm in order to ensure the simultaneous melting only of arelatively thin layer. As a consequence, compacting takes place inregular, narrow bands providing thereby a fully compacted agglomerate.

According to another preferred embodiment, the height of the heatingelement is larger than 60 mm, but the device can be adjusted so that thebottle intrudes into the heating element only in a section shorter than60 mm.

The apparatus according to the invention allows an efficient, regulatedcompacting of plastic bottles so that the bellows-like folding occurs onshort sections. This can be achieved partly by the small-height heatingelement, partly by controlled compacting. Compacting can be controlledby changing the flow cross section of the airing duct in the plug.

From the viewpoint of controlled and efficient compacting it is alsoimportant that melting and pressing takes always place starting from themouth piece of the bottle, so that the pieces of smaller diameter can beeasily compacted into the following pieces of larger diameter.

In order to obtain maximum compacting, a preferred embodiment isprovided with additional, mechanical compacting means.

Further details of the invention will be explained by means ofembodiments illustrated in the enclosed drawings, wherein

FIG. 1 is a section of a preferred embodiment of the invention;

FIG. 2 is an enlarged section of the plug in the lid of the embodimentshown in FIG. 1;

FIG. 3 is a partly sectioned view of another embodiment according to theinvention during compacting;

FIG. 4 shows part of an embodiment provided with a mechanicalafter-compactor and

FIG. 5 a photo of a bottle compacted with the apparatus according to theinvention compared with a bottle compacted by a traditional method.

The device shown in FIG. 1 comprises a base 1, a housing 2, spring means3 and a bottle holder 4 in housing 2. Bottle holder 4 is kept in upperposition by the spring means 3. At the upper part of housing 2, thereare heating element 6 and lid 5.

In lid 5, there is a plug 7 with an air outlet channel 10 for allowingthe air to flow out during pressing.

In use, the bottle 15 to be compacted is placed into the bottle holder4, and pressed down together with it until impacting on the base 1. Withscrewing the lid 5 into the heating element, 6 the bottle is fixed, thenthe plug 7 is sealed in the mouth-piece of the bottle. After startingthe heating, spring means 3 presses the bottle upwards, and as theplastic melts in thin layers, it is compressed continuously to abellow-like object until the compacting process ends by pressing theneck- and mouth-piece into the middle of the agglomerate.

FIG. 2 shows the the plug 7 in lid 5. A threaded adjusting sleeve 9 anda ball valve 8 is arranged in the air outlet channel 10 of plug 7 foradjusting the free cross section of channel 10. Setting the appropriatespring force in ball valve 8 may be carried out by means of sleeve 9 sothat it is drawn upwards or downwards by a screwdriver therebycontrolling the amount and/or flow rate of the air.

Sleeve 9 is screwed into a tube 11 with a threaded section 12 at theupper end. In this way, tube 11 can be raised and lowered by turning theplug 7. When raised, an elastic sleeve 14 between an outer flange of thetube 11 and a bush 13 is compressed and, at the same time, its diameterincreases. Thus, the mouth piece of the bottle 15 to be compacted issealed. After this, air can flow out only through the air outlet channel10, controlled by ball valve 8.

Melting of a short section of the bottle 15 is performed by heatingelement 6 shown in FIG. 3, with reference to another embodiment of theinvention. The height of heating element 6 is preferably smaller than 60mm, in order to keep small the height of the section melted at once,thus making compacting uniform and regular.

The height of the heating element 6 can also be larger than 60 mm, inorder to ensure an increased heating potential, but than only a sectionof it (preferably smaller than 60 mm) is used for direct melting of thebottle. In this case, bush 13 of the plug 7 seen in FIG. 2 is coupled tothe lid 5 by an external thread to enable lowering the bottle 15 withrespect to the heating element 6 in the lid 5. In this position, asection of the bottle 15 smaller than 60 mm is heated only.

In the embodiment shown in FIG. 3, lid 5 is movable on guide bars 16,and compacting power is gained from the weight of the lid. As a result,the bottle 15 is folded gradually in narrow bands, while air leavesthrough the air outlet channel 10 of the plug 7 in a controlled manner.

FIG. 4 shows an embodiment in which the bottle compacted by the weightof the lid (5) can be further compacted by mechanical means. For thisadditional compacting a gear rim 18 is turned by means of a lever 17 ona gear rack 19 fastened to the lid 5. In this way, the agglomerate ofthe bottle 15 is further compacted before it cools down. Though thecompression in the examples shown above was provided by the weight ofthe lid, many other possible embodiments like spindles driven byelectric motors can also be used for compacting the bottles.

It is to be noted that the above non limiting examples shown in thedisclosure only illustrate the invention, it is obvious that a skilledperson can make other variants without going beyond the scope of theclaims enclosed. In these variants compacting can take place by anymeans of, the apparatus may be closed, or open like the one shown, andthe lid may also have many different embodiments.

The basic advantage of the device according to the invention is that, tothe contrary of most known devices, compacting starts at the neck pieceof the bottle, and narrow melted bands are produced during compaction.Moreover, the air flow-out can also be controlled to maintain optimalconditions for compacting. Due to these factors, the agglomerate has aregular shape and the smallest possible size, since the narrowersections disappear in the bellows-like folded parts. Thereby—as is shownin FIG. 5—the volume of the waste is significantly reduced as comparedto the state of art. Furthermore, as it provides a simple andinexpensive way for compacting the bottles, the number of thrown awaybottles loading the environment will also probably be reduced.

1. Apparatus for compacting empty plastic bottles, comprising a housingor frame for receiving the bottle, an element for fixing the bottle, aheating element surrounding part of the bottle and compressing means forcompacting the softened bottle, characterized in that the housing orframe is constructed to receive the bottle (15) with its mouth partupwards? the heating element (6) or the part of the heating element (6)surrounding the bottle (15) is at most 60 mm high, and is arrangedaround the neck part of the bottle (15) in its starting position and thefixing element is a sealable plug (7) in the compressing means, to befitted into the mouth of the bottle (15) and having an air channel (10).2. Apparatus according to claim 1 characterized in that the crosssection of the air channel (10) is adjustable.
 3. Apparatus according toclaim 1 characterized in that the compression means and the fixingelement for the bottle (15) is a lid (5) moving on vertical guide bars(16).
 4. Apparatus according to claim 3 characterized in that the lid(5) is compressing the bottle (15) towards the base of the housing, byits weight.
 5. Apparatus according to claim 4 characterized in that thelid (5) is lifted and lowered by a spindle driven by an electric motor.6. Apparatus according to claim 4 characterized in that the lid (5) islifted by spring means (3).
 7. Apparatus according to claim 1characterized in that in the air channel (10) of the plug (7) isprovided with flow control means.
 8. Apparatus according to claim 7characterized in that the flow control means is a valve.
 9. Apparatusaccording to claim 1 characterized in that the diameter of least onesection of the plug (7) is adjustable.
 10. Apparatus according to claim9 characterized in that the section of adjustable diameter is an elasticrubber or plastic sleeve (9).
 11. Apparatus according to claim 1characterized in that the height of the heating element (6) is at most60 mm.
 12. Apparatus according to claim 1 characterized in that theheating element (6) is arranged in a position to surround the bottle(15) in a height of at most 60 mm.
 13. Apparatus according to claim 1characterized in that mechanical means for additional compacting areprovided.
 14. Apparatus according to claim 13 characterized in that theadditional mechanical compacting means is a gear rim (18) gearing in agear rack (19) on the back side of the lid (5), wherein the gear rim(18) is provided with a manually operated lever.